1. Field of the Invention
The present invention relates to a method for transmitting control signals and pixel data signals to source drivers of a liquid crystal display (LCD), and more particularly relates to a data transmission method between a timing controller and source drivers of a LCD.
2. Description of the Related Art
FIG. 1 illustrates a circuitry of a conventional LCD. The conventional LCD includes a group of source drivers 13, a group of gate drivers 14, an LCD panel 11 and a timing controller 12. As shown in FIG. 1, a video processing system 15 transmits RGB data and control signals including a clock signal, a horizontal synchronizing signal and a vertical synchronizing signal to a timing controller 12. The timing controller 12 rearranges and transfers the RGB data, and outputs essential control signals to the source driver 13.
An RSDS (reduced swing differential signaling) interface circuit or TTL (single edge of transistor transistor logic) interface circuit is typically used between the timing controller 12 and the group of source drivers 13. In the RSDS or TTL interface, each value of the pixel of red, green or blue is represented by 6 bits, which necessitates 18 wire lines for RGB data transmission. With the demands of higher color resolution and image quality, the number of bits of the pixel value should be increased, for example, to 8 or 10. Furthermore, increasing the bits of the pixel value will necessitates more wire lines and therefore result in a larger power consumption, more serious EMI (electromagnetic interference) effect and higher fabrication cost.
The trends in the LCD TV market are towards larger size panels and higher resolutions to support true HDTV formats. In addition to the size and the data rate requirements, the LCD TV is also demanding improved visual performance. This includes improved response time of the liquid crystal, more accurate and stable color temperature, higher contrast ratios, higher brightness, and higher color depth. What was need was an interface that was developed from the ground up to meet the needs of the LCD TV market of today with an eye on the flexibility that will be needed in the future.